TWI836590B - Optical body, master disk, and manufacturing method of optical body - Google Patents

Abstract

The present invention provides a novel and improved optical body, a master disk, and a manufacturing method of the optical body that can further improve anti-reflective properties and are easy to manufacture. In order to solve the above problems, according to one aspect of the present invention, an optical body is provided, which is an optical body having a concave and convex structure in which convex or concave structures are arranged with an average period below the wavelength of visible light. , the structure has an asymmetric shape in any plane direction perpendicular to the thickness direction of the optical body. Based on the above point of view, the anti-reflective properties can be further improved and can be easily produced.

Description

Optical body, master disc, and method for manufacturing optical body

The present invention relates to an optical body, a master disk, and a manufacturing method of the optical body.

Generally speaking, in order to reduce surface reflection and increase transmitted light in display devices such as televisions and optical components such as camera lenses, reflection elimination processing is performed on the light incident surface. Such reflection elimination processing is, for example, proposed as a method of forming an optical body with a concave and convex structure on the light incident surface. Here, the uneven structure formed on the surface of the optical body forms a plurality of convex parts and concave parts, and the arrangement pitch between the convex parts and the arrangement pitch between the concave parts is below the wavelength of visible light.

In this way, the refractive index change of the surface of the optical body to incident light becomes gentle, so there is no sudden refractive index change that causes reflection. Therefore, by forming such a concave and convex structure on the surface of the light incident surface, reflection of incident light in a wide wavelength band can be suppressed.

Patent Documents 1 to 3 disclose technologies related to such optical bodies. The technology disclosed in Patent Document 1 is to prevent defects in the convex parts of the transferred product caused by poor filling of the transfer material in the mold, peeling resistance, and collapse of the convex part pattern of the transferred fine uneven structure, which is randomly distributed on the surface of the optical body. Arrange the dense areas of convex parts.

The technology disclosed in Patent Document 2 is to suppress the generation of diffraction light by shifting the arrangement pattern of concave and convex from the arrangement pattern of regular polygons. The technology disclosed in Patent Document 3 is to easily control the arrangement pitch of concave and convex, etc., and to randomly form concave and convex by sputtering. The technology disclosed in Patent Document 4 is to arrange concave and convex with symmetrical shapes in a predetermined arrangement pattern. Prior Art Documents Patent Documents

Patent document 1: Japanese Patent Publication No. 2014-066976 Patent document 2: Japanese Patent Publication No. 2015-038579 Patent document 3: Japanese Patent Publication No. 2015-060983 Patent document 4: Japanese Patent Publication No. 2009-258751

Summary of the invention Problems to be solved by the invention However, the techniques disclosed in patent documents 1 to 4 are still insufficient for the anti-reflection properties of optical bodies. In addition, as a method for improving the anti-reflection properties of optical bodies, a method of overlapping convex parts to form a concave-convex structure as disclosed in patent document 4 has been proposed. According to this method, since the density of the concave-convex structure can be increased, it is expected that the anti-reflection properties of the optical body can be improved. However, when this method is used in the conventional concave-convex structure, in order to achieve the desired anti-reflection properties, the convex parts need to be overlapped to a large extent. Therefore, there is another problem that the transferability of the concave-convex structure of the master disc is deteriorated. Means for solving the problem

In other words, the optical body is manufactured using a master disk having a concave-convex structure formed on the surface as a transfer mold. The concave-convex structure formed on the surface of the master disk has a complementary shape to the concave-convex structure formed on the surface of the optical body. The method is to form an uncured resin layer on a substrate and transfer the concave-convex structure of the master disk to the uncured resin layer. Thereafter, the uncured resin layer is hardened. Next, the master disk is peeled off from the hardened uncured resin layer, i.e., the hardened resin layer. The concave-convex structure of the master disk is transferred to the hardened resin layer. The optical body is manufactured by the above steps. Here, when the convex portions are largely overlapped with each other, the concave portion will become a very fine shape. In other words, the bottom area of the concave portion becomes very small. Therefore, the convex parts formed on the master disc become very fine shapes. Therefore, it is very difficult to correctly transfer the concave-convex structure of the master disc to the uncured resin layer. In other words, the transferability of the concave-convex structure of the master disc deteriorates. Moreover, when the transferability deteriorates, the concave-convex structure of the master disc cannot be correctly reflected on the optical body, so the anti-reflection characteristics of the optical body may deteriorate.

Therefore, the present invention is made in view of the above-mentioned problems. The purpose of the present invention is to provide a novel and improved optical body, a master plate, and a method for manufacturing an optical body that can further enhance the anti-reflection properties and is easy to manufacture. Means for solving the problem

In order to solve the above problems, according to one aspect of the present invention, an optical body is provided, which is an optical body having a concave and convex structure in which convex or concave structures are arranged with an average period below the wavelength of visible light. Thus, the structure has an asymmetric shape in any plane direction perpendicular to the thickness direction of the optical body.

Here, the top view shape of the structure may have an asymmetric shape in one surface direction.

Furthermore, a straight line is used to divide a quadrilateral circumscribed to the structure into two equal parts along the arrangement direction of the structure. When the top view shape of the structure is divided into two regions by the aforementioned straight line, the respective areas may also be different.

Furthermore, of the two regions, the area ratio obtained by dividing the area of the smaller region by the area of the larger region may be 0.97 or less.

Moreover, the area ratio may be 0.95 or less.

Moreover, the area ratio may be 0.95 or less and 0.33 or more.

In addition, the vertical cross-sectional shape of the structure may have an asymmetric shape in one direction.

Furthermore, the vertex position of the vertical cross-sectional shape of the structure may also be displaced in the orbital direction relative to the center point of the structure in the orbital direction.

In addition, the displacement ratio obtained by dividing the displacement amount of the vertex position by the point pitch of the structure may be 0.03 or more.

Moreover, the displacement ratio may be 0.03 or more and 0.5 or less.

Furthermore, the arrangement pitch in one surface direction of the structure may be different from the arrangement pitch in the other surface direction of the concave-convex structure.

Moreover, the structure may have a convex shape.

Moreover, the structure may have a concave shape.

In addition, the structure may be composed of a cured product of curable resin.

Furthermore, adjacent structures may be connected to each other.

According to another aspect of the present invention, there is provided a master disk having a complementary shape with the aforementioned concave and convex structures formed on its surface.

Here, the mother disk may also be plate-shaped, cylindrical, or cylindrical.

According to another aspect of the present invention, a method for manufacturing an optical body is provided, which uses the above-mentioned master as a transfer mold and forms a concave-convex structure on a substrate.

Based on the aforementioned viewpoint, the structure has an asymmetric shape in any plane direction perpendicular to the thickness direction of the optical body. Therefore, high anti-reflection properties can be achieved even if the structures are greatly superimposed on each other. Therefore, since the transferability of the concave and convex structure of the master disk is high, the production of the optical body becomes easy. Invention effect

As explained above, based on the above point of view, the anti-reflective properties can be further improved and can be easily produced.

Form used to implement the invention Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. In addition, in this specification and the drawings, structural elements that have substantially the same functional structure are assigned the same reference numerals to omit repeated description.

＜1. Structure of optical body＞ Next, the structure of the optical body 10 will be described based on FIGS. 1 to 3 . The optical body 10 has a base material 11 and an uneven structure 12 formed on one side surface of the base material 11 . Furthermore, the base material 11 and the concave-convex structure 12 may also be integrally formed. For example, if the base material 11 is a thermoplastic resin film, the base material 11 and the concave-convex structure 12 can be integrally formed. Details will be discussed later.

The concave-convex structure 12 has a plurality of convex portions 13 (structure) that are convex in the film thickness direction of the optical body 10 and a plurality of concave portions 14 (structure) that are concave in the film thickness direction of the optical body 10 . The convex portions 13 and the concave portions 14 are periodically arranged on the optical body 10 . For example, in the example of FIG. 1 , the convex portions 13 and the concave portions 14 are arranged in a regular hexagonal grid shape (that is, a symmetrical houndstooth shape).

In other words, the concave-convex structure 12 has tracks (rows) composed of a plurality of convex portions 13 and concave portions 14 arranged in parallel to each other. Furthermore, there is no particular limitation on which direction the convex portions 13 and the concave portions 14 arranged in the trajectory are defined. However, for example, when the optical body 10 is a long optical body (or an optical body obtained by cutting a long optical body), The convex portions 13 and the concave portions 14 arranged in the length direction of the long optical body can also be defined as tracks. In the example in Figure 1, the trajectory is defined according to this method. Specifically, in the example of FIG. 1 , the trajectories extend in the direction of arrow B (that is, the left and right direction) and are arranged in the up and down direction. In addition, the convex portions 13 (or the recessed portions 14) arranged between adjacent tracks are offset from each other by only half the length of the convex portions 13 (or the recessed portions 14) in the longitudinal direction of the tracks (ie, the track direction).

Of course, the convex portions 13 and the concave portions 14 may be arranged in other arrangement patterns. For example, the convex portions 13 and the concave portions 14 may be arranged in other regular polygonal grids (e.g., rectangular grids). Furthermore, the convex portions 13 and the concave portions 14 may be arranged in a skewed polygonal grid. Furthermore, the convex portions 13 and the concave portions 14 may be arranged randomly.

Furthermore, the convex portion 13 has an asymmetric shape in any plane direction perpendicular to the thickness direction of the optical body 10. In the example of FIG. 1 , the convex portion 13 has an asymmetric shape in the direction of arrow B. In other words, the convex portion 13 has a shape in which the symmetric shape is tilted toward the direction of arrow B. The shape of the convex portion 13 is described in detail below.

As shown in FIG3 , in this embodiment, the top view shape of the protrusion 13 is asymmetric in the direction of arrow B. Here, the top view shape of the protrusion 13 is the shape obtained by projecting the protrusion 13 onto a plane perpendicular to the thickness direction of the optical body 10 (i.e., the shape shown in FIG1 or FIG3 ).

Next, draw a quadrangle X circumscribed to the top view shape of the convex portion 13. Here, the quadrangle X means the smallest quadrangle among the quadrilaterals that contain the top view shape of the convex portion 13. Then, the quadrangle X is bisected by a line segment X1 perpendicular to the arrow B. Here, the line segment X1 is a line segment used to bisect the quadrangle X along the arrangement direction of the convex portions 13. And, the midpoint A of the line segment X1 is defined as the center point of the convex portion 13 (that is, the center point in the trajectory direction of the convex portion 13). The top view shape of the convex portion 13 is divided into two regions X11 and X12 by the line segment X1. In addition, "the top view shape of the convex portion 13 is asymmetric in the direction of the arrow B" means that the regions X11 and X12 are asymmetric to the line segment X1. In other words, the areas of the regions X11 and X12 are different. Therefore, the top view shape of the convex portion 13 becomes a shape symmetrical to the line segment X1 (for example, a perfect circle) and tilted in the direction of arrow B. Although the area ratio of region X11 to region X12 is not particularly limited, it is preferably less than 0.97, more preferably less than 0.95, and even more preferably less than 0.95 and more than 0.33. When the area ratio is less than 0.97, the base area described later can be increased. In addition, when the top view shape of the convex portion 13 is the limit of physical asymmetry, that is, when it is a triangular shape (refer to Figure 26), the area ratio is 0.33. Therefore, the preferred range of the lower limit value is set to 0.33. Here, the area ratio of region X11 to region X12 is obtained by dividing the smaller area by the larger area of region X11 and region X12. In this case, the anti-reflection property of the optical body 10 will be particularly improved. Furthermore, when the top view shape of the convex portion 13 is a perfect circle, the regions X11 and X12 become symmetrical shapes with respect to the line segment X1. Furthermore, the area ratios of the convex portions 13 may also be different. In this case, the area ratios of several convex portions 13 may be obtained and then the arithmetic average thereof may be obtained.

The top view shapes of the convex portions 13 can be separated from each other, contact each other (that is, the adjacent convex portions 13 are in contact with each other), or can also be partially overlapped with each other. In the example of FIG. 1 , the plan view shapes of the convex portions 13 are in contact with each other. From the viewpoint of improving the anti-reflective properties of the optical body 10, it is preferable that the plan view shapes of the convex portions 13 contact each other or partially overlap each other. However, when the plan view shapes of the convex portions 13 greatly overlap each other, the bottom area of the recessed portion 14 becomes smaller, thereby possibly deteriorating the transferability of the master 100 . Therefore, the plan view shapes of the convex portions 13 only need to be overlapped to an extent that the transferability of the master 100 is not deteriorated. In addition, the plan view shape can be observed using, for example, a scanning electron microscope (SEM) or a cross-sectional transmission electron microscope (cross-section TEM). When it is difficult to observe the boundaries of the structure in a plan view, it is also possible to observe the structure relative to the structure. The surface with a height of about 5% is processed into a cross-section to correspond to the shape of the bottom surface.

1 and 2 , in this embodiment, the CC cross-sectional shape (i.e., vertical cross-sectional shape) of the protrusion 13 is asymmetric in the direction of arrow B. Here, the CC cross-sectional shape refers to a cross-sectional shape passing through point A and parallel to the direction of arrow B and the thickness direction of the optical body 10 .

In addition, the apex 13a of the convex portion 13 is arranged on the CC cross-section. Furthermore, the vertex 13 a passes through the point A and is arranged at a position offset (displaced) from the straight line L1 parallel to the thickness direction of the optical body 10 . In other words, the position of the vertex 13 a of the vertical cross-sectional shape of the protrusion 13 is displaced in the trajectory direction relative to the center point A of the protrusion 13 in the trajectory direction. Specifically, the straight line L2 passing through the vertex 13 a and parallel to the thickness direction of the optical body 10 is only a distance T1 (the displacement amount of the vertex position) from the straight line L1 in the direction of arrow B. Therefore, "the vertical cross-sectional shape of the convex portion 13 is asymmetrical in the direction of arrow B" means that the vertex 13a is arranged at a position offset from the straight line L1 in the direction of arrow B. Therefore, the vertical cross-sectional shape of the convex portion 13 has a shape that is symmetrical on the straight line L1 and is tilted in the direction of the arrow B. Therefore, it can be said that the convex portion 13 is inclined in the direction of arrow B. Although the length of the distance T1 is not particularly limited, it is preferably 2% or more of the radius r of the plan view shape. Here, the radius r of the plan view shape means the distance from the intersection point of the CC cross section and the outer edge portion of the convex portion 13 to the center point. In addition, the value of distance L1 (nm) divided by the point pitch (nm) of the structure, that is, the displacement ratio (%) is preferably 0.03 or more, more preferably 0.03 or more and 0.5 or less, and more preferably 0.03 or more and 0.1 or less. . Furthermore, when the convex portions 13 and the concave portions 14 are randomly arranged, the displacement ratio is a value obtained by dividing the distance L1 by the average period of the uneven structure 12 . In addition, when the distance L1 is different in each structure 12, the distance L1 of several structures 12 may be calculated, and the arithmetic mean value may be used as the distance L1.

Furthermore, as shown in the example of FIG. 1 , the top view shape and the vertical cross-sectional shape of the protrusion 13 are both asymmetric in the direction of arrow B, but only one of the shapes may be asymmetric in the direction of arrow B. Furthermore, the protrusion 13 may be symmetric or asymmetric in the surface direction other than the direction of arrow B, but symmetry is preferred because it can improve the transferability of the master disc 100.

On the other hand, the recess 14 is arranged between the protrusions 13. In other words, the recess 14 is formed by the outer periphery of the protrusion 13. Therefore, the shape of the recess 14 must have the same characteristics as the protrusion 13. In other words, the top view shape and the vertical cross-sectional shape of the recess 14 are asymmetric in the direction of arrow B. The top view shape and the vertical cross-sectional shape of the recess 14 are defined to be the same as the top view shape and the vertical cross-sectional shape of the protrusion 13. Furthermore, the top view shape of the recess 14 becomes the shape of the opening surface of the recess 14, and the center of gravity of the top view shape of the recess 14 corresponds to the vertex 13a of the protrusion 13.

In this embodiment, since the convex portion 13 and the concave portion 14 are asymmetrical in the direction of the arrow B, as shown in the embodiment described later, even if the convex portions 13 are not overlapped or are not overlapped to a large extent, high anti-reflection characteristics can still be achieved. Therefore, in this embodiment, even if the overlapping portions of the convex portions 13 are not much, high anti-reflection characteristics can still be achieved. In other words, in this embodiment, even if the overlapping portions of the convex portions 13 are not much as shown in patent document 4, high anti-reflection characteristics can still be obtained. In addition, in this embodiment, the releasability of the master 100 is improved. In other words, in this embodiment, since the protrusion 13 is asymmetrical in the direction of arrow B, the master disk 100 can be easily peeled off from the optical body 10 by peeling off the master disk 100 from the optical body 10 in the direction of arrow B.

The shapes of the protrusion 13 and the recess 14 are not particularly limited as long as they meet the above requirements. The shapes of the protrusion 13 and the recess 14 may be, for example, cannonball-shaped, pyramidal, columnar, or needle-shaped.

Furthermore, the average period of the convex portion 13 and the concave portion 14 (the average period of the structure) is below the wavelength of visible light (for example, below 830nm), preferably above 100nm and below 350nm, preferably above 120nm and below 280nm, and more preferably 130-270nm. Therefore, the concavo-convex structure 12 becomes a so-called moth-eye structure. Here, when the average period is less than 100nm, it may be difficult to form the concavo-convex structure 12, so it is not good. Moreover, when the average period is greater than 350nm, it may cause diffraction of visible light, so it is not good.

Here, the average period of the convex portions 13 and the concave portions 14 is, for example, the arithmetic mean of the distances between the convex portions 13 and the concave portions 14 that are adjacent to each other. Furthermore, the uneven structure 12 can be observed by, for example, a scanning electron microscope (SEM) or a cross-sectional transmission electron microscope (cross-sectional TEM). The average period of the convex portion 13 can be measured by, for example, the following method. In other words, a plurality of combinations of adjacent convex portions 13 are selected. Furthermore, the distance between the vertices of the convex portions 13 is measured. In addition, the arithmetic mean of the measured values may be used as the average period of the convex portion 13 . In addition, the average period of the recessed portion 14 is measured by, for example, the following method. In other words, a plurality of combinations of adjacent recessed portions 14 are selected. Furthermore, the distance between the centers of gravity of the recessed portions 14 is measured. In addition, the average period of the recessed portion 14 can be calculated based on the arithmetic average of the measured values.

Furthermore, when the convex portions 13 and the concave portions 14 are periodically arranged on the optical body 10, the average period (ie, the average pitch) of the convex portions 13 and the concave portions 14 is divided into, for example, a point pitch L12 and a track pitch L13. The point pitch L12 is the average period between the convex portions 13 (or the concave portions 14) arranged in the longitudinal direction of the track. The track pitch L13 is the average period between the convex portions 13 (or the recessed portions 14) arranged in the arrangement direction of the tracks (up and down direction in FIG. 1). In this embodiment, both the point pitch L12 and the track pitch L13 are below the wavelength of visible light. The point pitch L12 and the track pitch L13 may be the same or different. The average period of the convex portion 13 and the concave portion 14 is the arithmetic mean of the point pitch L12 and the track pitch L13.

In addition, the height of the protrusion 13 (i.e., the depth of the recess 14) is not particularly limited, but is preferably between 100 nm and 300 nm, more preferably between 130 nm and 300 nm, and most preferably between 150 nm and 230 nm.

By setting the average period and height of the concave-convex structure 12 to values within the aforementioned range, the anti-reflective properties of the optical body 10 can be further improved. Specifically, the lower limit of the spectral reflectance (spectral regular reflectance at a wavelength of 350 to 800 nm) of the uneven structure 12 can be set to about 0.01 to 0.1%. Moreover, the upper limit value can be set to 0.5% or less, preferably 0.4% or less, more preferably 0.3% or less, more preferably 0.2% or less. In addition, when the uneven structure 12 is formed by a transfer method as described later, the optical body 10 can be easily peeled off from the master disk 100 after transfer. Furthermore, the heights of the protrusions 13 can also be different for each protrusion 13 .

The concavoconvex structure 12 is composed of a hardened material such as a hardening resin. The hardened material of the hardening resin is preferably transparent. The hardening resin contains a polymerizable compound and a hardening initiator. The polymerizable compound is a resin hardened by a hardening initiator. Examples of the polymerizable compound include epoxy polymerizable compounds and acrylic polymerizable compounds. The epoxy polymerizable compound is a monomer, oligomer, or prepolymer having one or more epoxy groups in the molecule. Examples of epoxy polymerizable compounds include various bisphenol-type epoxy resins (bisphenol A type, bisphenol F type, etc.), novolac-type epoxy resins, various modified epoxy resins such as rubber and urethane, naphthalene-type epoxy resins, biphenyl-type epoxy resins, phenol novolac-type epoxy resins, stilbene-type epoxy resins, trisphenol methane-type epoxy resins, dicyclopentadiene-type epoxy resins, triphenylmethane-type epoxy resins, and prepolymers thereof.

Acrylic polymerizable compounds are monomers, oligomers, or prepolymers having one or more acrylic groups in the molecule. Here, monomers are further classified into monofunctional monomers having one acrylic group in the molecule, bifunctional monomers having two acrylic groups in the molecule, and multifunctional monomers having three or more acrylic groups in the molecule.

Examples of "monofunctional monomers" include: carboxylic acid (acrylic acid), hydroxyl type (2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate), alkyl group or alicyclic type Monomers (isobutylacrylate, t-butylacrylate, isooctyl acrylate, lauryl acrylate, octadecyl acrylate, isobornyl acrylate, cyclohexyl acrylate), other functional properties Monomers (2-methoxyethyl acrylate, methoxyethylene glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofuran methacrylate, benzyl acrylate, ethyl carbitol acrylate , phenoxyethylacrylate, N,N-dimethylaminoethylacrylate, N,N-dimethylaminopropylacrylamide, N,N-dimethylacrylamide, propylene base Phinoline, N-isopropylacrylamide, N,N-diethylacrylamide, N-vinylpyrrolidone, 2-(perfluorooctyl)ethyl acrylate, 3-perfluorohexyl-2- Hydroxypropyl acrylate, 3-Perfluorooctyl-2-hydroxypropyl-acrylate, 2-(Perfluorodecyl)ethyl-acrylate, 2-(Perfluoro-3-methylbutyl)ethyl acrylate), 2,4,6-tribromophenol acrylate, 2,4,6-tribromophenol methacrylate, 2-(2,4,6-tribromophenoxy)ethyl acrylate ), 2-ethylhexyl acrylate, etc.

Examples of the "bifunctional monomer" include tri(propylene glycol) diacrylate, trimethylolpropane-diallyl ether, urethane acrylate, and the like.

Examples of the “multifunctional monomer” include trihydroxymethylpropane triacrylate, dipentatriol pentaacrylate and dipentatriol hexaacrylate, and ditrihydroxymethylpropane tetraacrylate.

Examples other than the acrylic polymerizable compounds listed above include: acrylic acid-based In some embodiments, the polymerizable compound may be acrylate, polyol, glycerol acrylate, polyether acrylate, N-vinyl formamide, N-vinyl caprolactone, ethoxy diethylene glycol acrylate, methoxy triethylene glycol acrylate, polyethylene glycol acrylate, EO-modified trihydroxymethyl propane triacrylate, EO-modified bisphenol A diacrylate, aliphatic urethane oligomer, polyester oligomer, etc. From the viewpoint of transparency of the optical body 10, the polymerizable compound is preferably an acrylic polymerizable compound.

The hardening initiator is a material that hardens curable resin. Examples of the hardening initiator include thermal hardening initiators, photohardening initiators, and the like. The hardening initiator may be hardened by any energy ray other than heat or light (eg, electron beam). When the curing initiator is a thermosetting initiator, the curable resin is a thermosetting resin. When the curing initiator is a photocuring initiator, the curing resin is a photocurable resin.

Here, from the viewpoint of the transparency of the optical body 10, the curing initiator is preferably an ultraviolet curing initiator. Therefore, the curable resin is preferably ultraviolet curable acrylic resin. Ultraviolet curing initiator is a type of photocuring initiator. Examples of ultraviolet curing initiators include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexylbenzophenone, and 2-hydroxy-2-methyl-1- Take phenylpropan-1-one, etc. as an example.

Furthermore, the resin constituting the concavo-convex structure 12 may be a resin imparted with functional properties such as hydrophilicity, water repellency, and antifogging.

In addition, additives may be added to the concavo-convex structure 12 according to the purpose of the optical body 10. Examples of such additives include inorganic fillers, organic fillers, leveling agents, surface conditioners, defoaming agents, etc. Examples of inorganic fillers include metal oxide particles such as _SiO2 , _TiO2 , _ZrO2 , _{SnO2 ,} and _Al2O3 .

The type of the base material 11 is not particularly limited, but when using the optical body 10 as an anti-reflective film, a film that is transparent and difficult to break is preferred. Examples of the base material 11 include PET (polyethylene terephthalate) film or TAC (triacetyl cellulose) film. When using the optical body 10 as an anti-reflection film, it is preferable that the base material 11 is made of a material with excellent transparency. In addition, the thickness of the base material 11 may be rationally and appropriately adjusted according to the purpose of the visible optical body 10 , that is, the required position of the optical body 10 . The base material 11 may also be made of silicon-based material. In addition, the shape of the base material 11 is not particularly limited to a film shape, and various shapes such as plate shape, curved surface shape, and lens shape may be used. In addition, the material of the base material 11 is an inorganic material, and for example, a glass material or an Al ₂ O ₃ based material can also be used. The base material 11 and the concave-convex structure 12 may be made of different materials or may be made of the same material. When the base material 11 and the concave-convex structure 12 are made of different materials, a refractive index matching layer for adjusting the refractive index may also be formed between them. The thickness of the base material 11 may also be, for example, 50~125 μm. The base material 11 may be flat or in other shapes (such as concave or convex). In addition, at least one of the base material 11 and the uneven structure 12 may be colored.

<2. Variations of the concavo-convex structure> (2-1. First variation) Next, various variations of the concavo-convex structure are described. FIG. 4 shows the first variation of the concavo-convex structure 12. In the first variation, the top view shape of the convex portion 13 is slightly flatter in the vertical direction compared to the top view shape shown in FIG. 1. The first variation can also be expected to have the same effect as the concavo-convex structure 12 in FIG. 1.

(2-2. Second modification) FIG. 5 shows a second modification of the concave and convex structure 12. In the second modification, the arrangement pattern of the convex portions 13 and the concave portions 14 is a pattern shifted from the regular hexagonal pattern. Specifically, in the second modification, the track pitch L3 is slightly narrower than the track pitch L3 shown in FIG. 1 . In the second modification example, the same effects as those of the concave and convex structure 12 in FIG. 1 can also be expected. Furthermore, in order to obtain the concave and convex structure 12 like the second modification, the track pitch and the point pitch can be appropriately changed. For example, set the track pitch to 100~180nm and the point pitch to 180~270nm.

(2-3. Third modification) FIG. 6 shows a third modification example of the concave and convex structure 12. The up and down directions in Fig. 6 are the trajectory directions (corresponding to the direction of arrow B). In the third modification, the convex portion 13 has an asymmetric shape in a direction different from the trajectory direction (here, the upper right direction). In other words, the plan view shape of the convex portion 13 becomes an asymmetric shape in the upper right direction. For example, when the same areas X11 and X12 as in FIG. 3 are defined, the upper right area X11 is larger than the lower left area X12. In addition, the vertex 13a is shifted in the upper right direction from the center point A. In the third modification example, the same effects as those of the concave and convex structure 12 in FIG. 1 can also be expected. Furthermore, in order to obtain the concave and convex structure 12 as shown in FIG. 6 , in the exposure device 200 described below, an asymmetrically shaped aperture may be provided on the front side of the field lens 223 in the optical path direction. The top view shape of the aperture is slightly consistent with the top view shape of the convex portion 13 . By arranging such an aperture, the laser light collected as an image after Fourier transformation by the field lens 223 can have an asymmetric shape.

(2-4. The fourth variant) In the fourth variant, the concave-convex structure 12 has a complementary shape to the concave-convex structure 12 shown in FIG. 1. In other words, in the fourth variant, the convex portion 13 and the concave portion 14 in FIG. 1 are swapped, and the concave portion 14 and the convex portion 13 in FIG. 1 are swapped. FIG. 7 shows a CC cross-sectional view of the concave-convex structure 12 of the fourth variant. The same effect as the concave-convex structure 12 of FIG. 1 can also be expected in the fourth variant. At this time, the top view shape and the vertical cross-sectional shape of the concave portion 14 become asymmetric in the direction of arrow B. The top view shape and the vertical cross-sectional shape of the concave portion 14 are defined to be the same as the top view shape and the vertical cross-sectional shape of the convex portion 13 shown in FIG. 1. Furthermore, the top view shape of the concave portion 14 becomes the shape of the opening surface of the concave portion 14, and the center of gravity of the top view shape of the concave portion 14 corresponds to the vertex 13a of the convex portion 13 shown in FIG. 1.

＜3. Structure of the master disk＞ The concave-convex structure 12 is produced using, for example, the master 100 shown in FIG. 8 . Therefore, next, the structure of the master disk 100 will be described. The master disk 100 is, for example, a master disk used in the nano stamping method, and has a cylindrical shape. The master disk 100 may be cylindrical or in other shapes (eg, flat plate). However, when the master disk 100 is cylindrical or cylindrical, the concave and convex structure 120 of the master disk 100 (ie, the concave and convex structure of the master disk) can be seamlessly transferred to a resin substrate or the like through a roll-to-roll method. Thereby, the optical body 10 to which the master concave and convex structure 120 of the master 100 is transferred can be produced with high productivity. From this point of view, the shape of the master disk 100 is preferably cylindrical or cylindrical.

The master 100 has a master substrate 110 and a master concave-convex structure 120 formed on the periphery of the master substrate 110. The master substrate 110 is, for example, a glass body, and specifically, is formed of quartz glass. However, the master substrate 110 is not particularly limited as long as it has a high purity of _SiO2 , and may also be formed of fused quartz glass or synthetic quartz glass. The master substrate 110 may be a metal base material on which the aforementioned materials are layered or a metal base material. The shape of the master substrate 110 is cylindrical, and may also be cylindrical or other shapes. However, as mentioned above, the master substrate 110 is preferably cylindrical or cylindrical. The master concave-convex structure 120 has a complementary shape to the concave-convex structure 12.

＜4.Manufacturing method of master disk＞ Next, a method of manufacturing the master disk 100 will be described. First, a base material photoresist layer is formed (film-formed) on the master base material 110 . Here, the photoresist material constituting the photoresist layer of the base material is not particularly limited, and may be either an organic photoresist material or an inorganic photoresist material. Examples of organic photoresist materials include phenolic varnish-based photoresist or chemically amplified photoresist. Examples of the inorganic photoresist include metal oxides containing one or more transition metals such as tungsten (W) or molybdenum (Mo). However, in order to perform thermal reactive photolithography, it is preferable to use a thermal reactive photoresist containing metal oxide to form the base photoresist layer.

When an organic photoresist is used, the substrate photoresist layer can be formed on the master substrate 110 by using spin coating, slit coating, dip coating, spray coating, or screen printing. In addition, when an inorganic photoresist is used for the substrate photoresist layer, the substrate photoresist layer can be formed by using a sputtering method.

Next, a portion of the base photoresist layer is exposed using the exposure device 200 (see FIG. 9 ) to form a latent image on the base photoresist layer. Specifically, the exposure device 200 modulates the laser light 200A and irradiates the laser light 200A to the base material photoresist layer. Thereby, since a part of the base material photoresist layer irradiated with the laser light 200A is modified, a latent image corresponding to the master concave and convex structure 120 can be formed on the base material photoresist layer. A latent image is formed on the photoresist layer of the base material with an average period below the wavelength of visible light.

Next, a developer is dripped onto the substrate photoresist layer on which the latent image is formed, and the substrate photoresist layer is developed. Thus, a concave-convex structure is formed on the substrate photoresist layer. Next, the substrate photoresist layer is used as a mask to etch the master substrate 110 and the substrate photoresist layer, and a master concave-convex structure 120 is formed on the master substrate 110. Furthermore, although the etching method is not particularly limited, dry etching with vertical anisotropy is preferred, such as reactive ion etching (RIE). The master 100 is manufactured by the above steps. Furthermore, anodized porous alumina obtained by anodizing aluminum can also be used as a master. Anodic oxidation of porous aluminum oxide is disclosed in, for example, International Publication No. 2006/059686. In addition, the master disk 100 can also be manufactured by using a stepper machine with a reticle mask having an asymmetric shape.

Although the details will be described later, in this embodiment, the master disc concavo-convex structure 120 is formed by adjusting the irradiation pattern of the laser light 200A. In this way, the shape of the master disc concavo-convex structure 120 can be made into a complementary shape of the concavo-convex structure 12. In other words, the shape of the master disc concavo-convex structure 120 becomes an asymmetric shape in any direction of the surface of the master disc 100 (here, the circumferential direction of the master disc 100).

＜5. Structure of exposure device＞ Next, the structure of the exposure device 200 will be described based on FIG. 9 . The exposure device 200 is a device for exposing the photoresist layer of the substrate. The exposure device 200 has a laser light source 201, a first mirror 203, a photodiode (PD) 205, a deflection optical system, a control mechanism 230, a second mirror 213, a moving optical table 220, a rotation axis motor 225, and a turntable 227. In addition, the master base material 110 is mounted on the turntable 227 so as to be rotatable.

The laser light source 201 is a light edge that can emit laser light 200A, for example, a solid laser or a semiconductor laser. The wavelength of the laser light 200A emitted by the laser light source 201 is not particularly limited, and may be, for example, a wavelength in the blue light band of 400 nm to 500 nm. In addition, the spot diameter of the laser light 200A (the diameter of the point irradiated to the photoresist layer) only needs to be smaller than the diameter of the opening surface of the concave portion of the master concave-convex structure 120, and is preferably about 200 nm, for example. The laser light 200A emitted from the laser light source 201 is controlled by the control mechanism 230 .

The laser light 200A emitted from the laser light source 201 travels in the form of a parallel beam, is reflected by the first mirror 203 and is guided to the deflection optical system.

The first mirror 203 is formed by a spectroscope and has the function of reflecting one of the polarized light components and transmitting the other polarized light components. The polarized light component transmitted through the first mirror 203 is converted into photoelectricity by the photodiode 205. The light receiving signal converted by the photodiode 205 is input to the laser light source 201, and the laser light source 201 performs phase modulation of the laser light 200A according to the input light receiving signal.

Furthermore, the deflection optical system includes a condenser lens 207 , an electro-optical deflector (EOD) 209 , and a collimator lens 211 .

In the deflection optical system, the laser light 200A is focused by the focusing lens 207 to the photoelectric deflection element 209. The photoelectric deflection element 209 is an element that can control the irradiation position of the laser light 200A. The exposure device 200 can also change the irradiation position of the laser light 200A guided to the moving optical stage 220 by the photoelectric deflection element 209 (i.e., Wobble mechanism). After the irradiation position of the laser light 200A is adjusted by the photoelectric deflection element 209, it is collimated again by the collimator lens 211. The laser light 200A emitted from the deflection optical system is reflected by the second mirror 213 and guided horizontally and parallelly to the moving optical stage 220.

The mobile optical stage 220 has a beam expander (BEX) 221 and a field lens 223 . The laser light 200A guided to the moving optical table 220 is shaped into a desired beam shape by the beam expander 221, and then irradiated through the field lens 223 onto the base photoresist layer formed on the master substrate 110. In addition, the moving optical table 220 moves in the arrow R direction (the conveyance pitch direction) by only one conveyance pitch (track pitch) every time the master base material 110 rotates. The master substrate 110 is placed on the turntable 227 . The rotating shaft motor 225 rotates the turntable 227 to rotate the master substrate 110 . Thereby, the laser light 200A is scanned on the photoresist layer of the base material. Here, a latent image of the photoresist layer of the base material is formed along the scanning direction of the laser light 200A. Therefore, the trajectory direction of the concave-convex structure 12 (ie, the direction of arrow B) corresponds to the scanning direction of the laser light 200A.

In addition, the control mechanism 230 has a formatter 231 and a driver 233, and controls the irradiation of the laser light 200A. The formatter 231 generates a modulation signal that controls the irradiation of the laser light 200A, and the driver 233 controls the laser light source 201 according to the modulation signal generated by the formatter 231 . Thereby, the irradiation of the laser light 200A to the master substrate 110 is controlled.

The formatter 231 generates a control signal for irradiating the base material photoresist layer with laser light 200A based on the input image drawn by any pattern drawn on the base material photoresist layer. Specifically, first, the formatter 231 obtains an input image drawn with any pattern drawn on the photoresist layer of the base material. The input image is equivalent to the image of the expanded view of the outer periphery of the base material photoresist layer after cutting the base material photoresist layer in the axial direction and flattening the outer periphery into a plane. Next, the formatter 231 divides the input image into small areas of a predetermined size (for example, divided into a grid shape), and determines whether each small area contains a drawing pattern. Then, the formatter 231 generates a control signal to control each small area judged to contain the drawing pattern to be irradiated with the laser light 200A. The control signal (ie, the exposure signal) is preferably synchronized with the rotation of the shaft motor 225, but may also be asynchronous. In addition, the synchronization between the control signal and the rotation of the shaft motor 225 can also be adjusted every time the master substrate 110 rotates. In addition, the driver 233 controls the output of the laser light source 201 according to the control signal generated by the formatter 231 . Thereby, the irradiation of the laser light 200A to the photoresist layer of the base material is controlled. Furthermore, the exposure device 200 can also perform well-known exposure control processing such as a focus servo device and position correction of the irradiation point of the laser light 200A. The focus servo device can use the wavelength of laser light 200A and can also use other wavelengths as a reference.

In addition, the laser light 200A irradiated from the laser light source 201 can also be branched through the optical system of most systems and then irradiated to the base material photoresist layer. At this time, a plurality of irradiation points are formed on the photoresist layer of the base material. At this time, when the laser light 200A emitted from one optical system reaches the latent image formed using other optical systems, the exposure may be completed.

<6. Example of laser light irradiation pattern> In this embodiment, the master concavo-convex structure 120 is formed on the master substrate 110 by adjusting the laser light irradiation pattern. An example of the laser irradiation pattern is the pulse shape of the laser light. Therefore, the pulse shape of the laser light is described.

Figure 10 shows a conventional example of pulse shape. The horizontal axis of Figure 10 shows the time, and the vertical axis shows the output level of the laser light. In the example of FIG. 10 , the exposure device 200 forms a master disk on the master substrate 110 by alternately irradiating the master substrate 110 with high-level (=Iw) laser light and low-level (=Ib) laser light. Concave-convex structure 120. Therefore, the pulse shape of the laser light is divided into a high-output pulse P1 and a low-output pulse P2. The base photoresist layer forms a latent image when irradiated with high-level laser light, but the shape of the latent image is also affected by low-level laser light. In this conventional example, the output level of the high output pulse P1 is Iw, and the output level of the low output pulse P2 is Ib. In addition, the output time of the high output pulse P1 and the output time of the low output pulse P2 are both t1. The master concave and convex structure 120 formed in this conventional example has a symmetrical shape in all plane directions. Therefore, the top view shape of the concave and convex structure 12 formed using the master disk 100 is, for example, a perfect circle. Moreover, the vertex 13a is arrange|positioned on the straight line L1 (refer FIG. 2).

FIG11 shows an example of the pulse shape of the present embodiment. In this example, the output level Ib1 of the low output pulse P2 is higher than the output level Ib of FIG10 . The inventors of the present invention have found that by making the output level Ib1 of the low output pulse P2 higher than the output level Ib of FIG10 , the shape of the master disc concave-convex structure 120 can be made asymmetric in the scanning direction of the laser light 200A. In other words, the master disc concave-convex structure 120 has a complementary shape that complements the concave-convex structure 12 shown in FIGS. 1 and 2 . In addition, the scanning direction of the laser light 200A is opposite to the direction of arrow B. The same is true in the following examples of FIGS. 12 to 14 . In this example, the time variation of the temperature of the photoresist layer of the substrate changes due to the change in the output level of the low output pulse P2. Therefore, it can be seen that the shape of the master disc concave-convex structure 120 is asymmetric in the scanning direction of the laser light 200A.

Furthermore, when the output difference between the output level Ib1 and the output level Ib is reduced, the area ratio of the area X11 and the area X12 becomes larger. In addition, the distance T1 between the straight line L2 and the straight line L1 (that is, the distance in the direction of arrow B from the vertex 13 a of the convex portion 13 to the center point A of the convex portion 13 . See FIG. 2 ) becomes larger. Furthermore, the output difference between the output level Ib1 and the output level Ib is preferably more than 30% of the output level Ib. Therefore, the area ratio of the region X11 and the region X12 can be set to a value within the above-mentioned preferred range. In addition, the ratio of the output level Iw to the output level Ib is preferably Iw:Ib=3:1, with Ib being the smaller value. Therefore, the concave-convex structure 12 can have an asymmetric shape in the direction of arrow B.

Furthermore, the output time of the high output pulse P1 and the low output pulse P2 per one cycle minute in the example of FIG. 11 is the same as that in the example of FIG. 10 . Therefore, the average period of the master disc concave-convex structure 120 formed by the example of FIG. 11 is roughly consistent with the average period of the master disc concave-convex structure 120 formed by the known example of FIG. 10 . The average period of the concave-convex structure 12 (specifically, the dot pitch L2) changes according to the output time of the high output pulse P1 and the low output pulse P2 per one cycle minute. Therefore, the output time of the high output pulse P1 and the low output pulse P2 per one cycle minute can be arbitrarily adjusted according to the anti-reflection characteristics required by the optical body 10. The same is also true in the following examples of FIG. 12 to FIG. 14 .

FIG12 shows an example of the pulse shape of the present embodiment. In this example, the output level Ib1 of the low output pulse P2 is higher than the output level Ib of FIG10 . In addition, the output time of the high output pulse P1 is t2 which is longer than t1. On the other hand, the output time t3 of the low output pulse P2 is also shorter than t2. In this example, the output time t3 of the low output pulse P2 is 2*t1-t2. The inventors have found that by making the output time t2 of the high output pulse P1 longer than the output time t3 of the low output pulse, the shape of the master disc concave-convex structure 120 can be made asymmetric in the scanning direction of the laser light 200A. In other words, the master disc concave-convex structure 120 has a complementary shape of the concave-convex structure 12 shown in Figures 1 and 2. In this example, since the output time of the high output pulse P1 changes, the time change of the temperature of the substrate photoresist layer changes. Therefore, it can be seen that the shape of the master disc concave-convex structure 120 is asymmetric in the scanning direction of the laser light 200A. Furthermore, in this example, the output level Ib1 of the low output pulse P2 is higher than the output level Ib of Figure 10. In addition, the output time of the high output pulse P1 is t2, which is longer than t1. Therefore, the degree of asymmetry is greater than the example of Figure 11. Therefore, for example, a convex portion 13 of the shape shown in Figure 4 is formed.

Furthermore, the longer the output time t2 of the high output pulse P1 is, the greater the area ratio of the region X11 to the region X12 is. Furthermore, the greater the distance T1 between the straight line L2 and the straight line L1 is. The relationship between the output time t2 and the output time t3 (t3/(t2+t3)) is preferably 40% or more and 90% or less. This allows the concavo-convex structure 12 to be asymmetrical in the direction of the arrow B.

FIG13 shows an example of the pulse shape of the present embodiment. In this example, the output level of the high output pulse P1 decreases linearly over time. The inventors have discovered that by causing the output level of the high output pulse P1 to decrease linearly over time, the shape of the master disc concave-convex structure 120 can be made asymmetric in the scanning direction of the laser light 200A. In other words, the master disc concave-convex structure 120 has a complementary shape to the concave-convex structure 12 shown in FIGS. 1 and 2 . In this example, the temporal variation of the temperature of the substrate photoresist layer also changes. Therefore, it can be seen that the shape of the master disc concave-convex structure 120 is asymmetric in the scanning direction of the laser light 200A.

In addition, the smaller the inclination of the output level of the high-output pulse P1 is (ie, the decrease in the output level per unit time becomes larger), the larger the area ratio between the region X11 and the region X12 is. Furthermore, the distance T1 between the straight line L2 and the straight line L1 becomes larger. Furthermore, the inclination of the output level of the high-output pulse P1 is preferably 97% or less with respect to Iw. Therefore, the concave-convex structure 12 can have an asymmetric shape in the direction of arrow B. In addition, the inclination of the output level of the high-output pulse P1 is preferably 50% or more relative to Iw. Therefore, the area ratio of the region X11 to the region X12 can be within the above-mentioned preferred range.

FIG. 14 shows an example of the pulse shape of this embodiment. In this example, the output level of the high output pulse P1 decreases step by step as time passes. The inventor found that by decreasing the output level of the high-output pulse P1 step by step over time, the shape of the master concave-convex structure 120 can be made asymmetrical in the scanning direction of the laser light 200A. In other words, the master concave and convex structure 120 has a complementary shape to the concave and convex structure 12 shown in FIGS. 1 and 2 . In this example, the time change of the temperature of the photoresist layer of the substrate also changes. Therefore, it can be seen that the shape of the master concave and convex structure 120 is asymmetrical in the scanning direction of the laser light 200A.

Furthermore, the greater the difference between the maximum value and the minimum value of the high output pulse P1, the greater the area ratio of the region X11 to the region X12. Furthermore, the distance T1 between the straight line L2 and the straight line L1 becomes larger. Furthermore, the difference between the maximum value and the minimum value of the high output pulse P1 is preferably 97% or less relative to Iw. This allows the concave-convex structure 12 to have an asymmetric shape in the direction of the arrow B. Furthermore, the difference between the maximum value and the minimum value of the high output pulse P1 is preferably 50% or more relative to Iw. This allows the area ratio of the region X11 to the region X12 to be a value within the above-mentioned preferred range.

In the example of FIG14 , the number of stages for decreasing the output level of the high output pulse P1 is 1 stage. Of course, the number of stages for decreasing the output level of the high output pulse P1 may be other stages. For example, by increasing the number of stages, it is expected that the shape of the convex portion 13 can be made smooth and easy to transfer.

Furthermore, in the examples of Figures 13 and 14, although a pulse whose output decreases with time is used, a pulse whose output increases can also be used. In this case, although the same effect as in the examples of Figures 13 and 14 can be obtained, the direction of asymmetry is almost opposite.

Furthermore, other irradiation modes of the laser light 200A can be exemplified by the shape of the laser spots formed by the laser light 200A on the photoresist layer of the base material. If the shape of the laser spot is asymmetric in the direction different from the scanning direction of the laser light 200A, the shape of the master concave and convex structure 120 can be asymmetric in the direction different from the scanning direction of the laser light 200A. Symmetrical shape. At this time, for example, the concave and convex structure 12 shown in FIG. 6 can be formed.

In addition, the specific output levels of the high-output pulse P1 and the low-output pulse P2 can be appropriately adjusted depending on the material of the photoresist layer of the base material, the wavelength of the laser light 200A, etc. In other words, the master concave and convex structure 120 of this embodiment can be formed on the master substrate 110 by adjusting the output levels of the high output pulse P1 and the low output pulse P2.

In addition, when using a heat-reactive photoresist as the base photoresist layer, the temperature distribution changes according to the power level of the irradiated pulse, so an asymmetric shape can be produced. In addition, when using a light-reactive photoresist as the base photoresist layer, the shape of the photoresist's reaction point changes according to the amount of light, so an asymmetric shape can be produced.

＜7. Manufacturing method of optical body using master disk＞ Next, an example of a method of manufacturing the optical body 10 using the master disk 100 will be described with reference to FIG. 14 . The optical body 10 can be manufactured by using a roll-to-roll transfer device 300 with a master 100 . In the transfer device 300 shown in FIG. 14 , the optical body 10 is made of photocurable resin.

The transfer device 300 includes a master plate 100 , a substrate supply roller 301 , a take-up roller 302 , guide rollers 303 , 304 , a rolling roller 305 , a peeling roller 306 , a coating device 307 , and a light source 309 .

The base material supply roller 301 is a roller for winding up the long base material 11 into a roll shape, and the winding roller 302 is a roller for winding up the optical body 10 . In addition, the guide rollers 303 and 304 are rollers for conveying the base material 11 . The roller 305 is a roller that closely adheres the base material 11 on which the uncured resin layer 310 is laminated, that is, the transfer film 3 a to the master 100 . The peeling roller 306 is a roller that peels off the base material 11 on which the uneven structure 12 is formed, that is, the optical body 10 , from the master disc 100 .

The coating device 307 has a coating device such as a coating device, and coats the uncured photocurable resin composition on the substrate 11 to form an uncured resin layer 310. The coating device 307 may also be, for example, a gravure coating device, a wire rod coating device, or a mold coating device. In addition, the light source 309 is a light source that emits light of a wavelength that can cure the photocurable resin composition, and may be, for example, an ultraviolet lamp.

In the transfer device 300, first, the substrate 11 is continuously fed from the substrate supply roller 301 through the guide roller 303. Furthermore, the substrate supply roller 301 can be changed to another batch of substrate supply rollers 301 during feeding. The uncured photocurable resin composition is coated on the fed substrate 11 by the coating device 307, and the uncured resin layer 310 is layered on the substrate 11. In this way, the transferred film 3a is produced. The transferred film 3a is closely attached to the master 100 by the roller 305. The light source 309 cures the uncured resin layer 310 by irradiating light to the uncured resin layer 310 closely attached to the master 100. Thereby, the master disc concave-convex structure 120 formed on the outer periphery of the master disc 100 is transferred to the uncured resin layer 310. In other words, a concave-convex structure 12 having a complementary shape to the master disc concave-convex structure 120 is formed on the substrate 11. Next, the substrate 11 formed with the concave-convex structure 12, that is, the optical body 10 is peeled off from the master disc 100 by the peeling roller 306. Then, the optical body 10 is taken up by the take-up roller 302 through the guide roller 304. Furthermore, the master disc 100 can be placed vertically or horizontally, and a mechanism for correcting the angle and eccentricity of the master disc 100 during rotation can also be provided. For example, an eccentric tilting mechanism can also be provided in the clamping mechanism.

In this way, the transfer device 300 conveys the transferred film 3 a by roller-to-roller, and transfers the peripheral shape of the master 100 to the transferred film 3 a. Thereby, the optical body 10 is produced.

Furthermore, when the optical body 10 is made of thermoplastic resin, the coating device 307 and the light source 309 are not needed. Furthermore, the base material 11 is made into a thermoplastic resin film, and a heating device is arranged on the upstream side of the master disk 100 . The base material 11 is heated by this heating device to make it soft, and then the base material 11 is pressed onto the master disk 100 . Thereby, the master concave and convex structure 120 formed around the master 100 is transferred to the base material 11 . Furthermore, the base material 11 may be a film made of a resin other than thermoplastic resin, and the base material 11 and the thermoplastic resin film may be laminated. At this time, the laminated film is heated with a heating device and then pressed onto the master disc 100 . Therefore, the transfer device 300 can continuously produce a transfer object, that is, the optical body 10, onto which the master concave and convex structure 120 formed on the master 100 is transferred.

Alternatively, a transfer film to which the master concave and convex structure 120 of the master 100 is transferred may be produced, and the transfer film may be used as a transfer mold to produce the optical body 10 . Alternatively, the master 100 may be copied by electroforming, thermal transfer, or the like, and the copy may be used as a transfer mold. In addition, the shape of the master disk 100 does not need to be limited to a roll shape, and it can also be a planar master disk. In addition to the method of using a photoresist to irradiate the laser light 200A, semiconductor exposure with a photomask, electron beam drawing, and mechanical processing can be optionally used. , anodizing and other processing methods.

Furthermore, when peeling the optical body 10 from the master disk 100, it is better to peel in the direction in which the convex portion 13 is asymmetric (in the example of FIG. 1 , the direction of arrow B). This is because the tilt direction of the convex portion 13 is consistent with the peeling direction of the optical body 10, and the optical body 10 can be peeled off from the master disk 100 more easily. In addition, the master concave-convex structure 120 of the master disk 100 can be transferred to the optical body 10 more reliably. Of course, in this embodiment, since the bottom area of the concave portion 14 is also sufficiently large, the optical body 10 can also be peeled off in other directions. In this case, the optical body 10 can also be easily peeled off from the master disk 100. Furthermore, the master disc concavo-convex structure 120 of the master disc 100 can be more reliably transferred to the optical body 10. [Example]

<1. Example 1> (1-1. Fabrication of optical body) In Example 1, a master 100 is fabricated by the following steps. A flat master substrate 110 made of thermally oxidized silicon is prepared. Then, a substrate photoresist layer is formed on the master substrate 110 by rotationally coating a positive photoresist material on the master substrate 110. Here, the photoresist material uses a metal oxide photoresist containing tungsten (W).

After that, a regular hexagonal latent image is formed on the substrate photoresist layer using the exposure device 200. Here, the wavelength of the laser light 200A is set to 405nm, and the NA of the field lens 223 is set to 0.85. In addition, the pulse shape of the laser light 200A is set to that shown in FIG. 11. In addition, the output level Iw of the high output pulse P1 is set to 9.5MW/ ^cm2 (the output level per unit area of the substrate photoresist layer), and the output level Ib1 of the low output pulse P2 is set to 1.6MW/ ^cm2 . In addition, the output time t1 of the high output pulse P1 and the low output pulse P2 is set to 20ns.

Then, the latent image is removed by dropping developer solution on the photoresist layer of the base material. In other words, development processing is performed. Then, dry etching is performed using the base photoresist layer as a photomask. Thereby, the master concave and convex structure 120 is formed on the master substrate 110 . CHF3 is used as the etching gas. After that, a fluorine-based release treatment agent is applied to the master concave and convex structure 120 .

Next, the optical body 10 is manufactured using the master 100 as a transfer mold. Specifically, a polyethylene terephthalate film is prepared as a substrate 11, and an uncured resin layer composed of an acrylic resin acrylate is formed on the substrate 11. Then, the master concave-convex structure 120 of the master 100 is transferred to the uncured resin layer. Then, the uncured resin layer is cured by irradiating the uncured resin layer with ultraviolet rays of 1000mJ/ ^cm2 . Thereafter, the optical body 10 is peeled off from the master 100 in the direction of arrow B (i.e., the track direction). The optical body 10 is manufactured by the above steps.

(1-2. Characteristic evaluation) The surface structure of the optical body 10 was confirmed by SEM and TEM. The SEM photograph is shown in FIG20. It can be clearly seen from FIG20 that the surface of the optical body 10 has a concave-convex structure 12. In addition, almost no defects of the concave-convex structure 12 were confirmed. Therefore, it can be confirmed that the transferability of the master 100 is good. The reason is that the bottom surface ratio is large, and the convex part 13 has an asymmetric shape in the direction of the arrow B, as described later. In addition, the dot pitch is 250nm, and the track pitch is 200nm.

Furthermore, the convex portion 13 is asymmetrical in the direction of arrow B. Specifically, the area ratio of the region X11 to the region X12 is 0.95. Furthermore, the height of the convex portion 13 is 180 nm. Furthermore, although the convex portions 13 are adjacent to each other, they are not overlapped.

Next, simulation is used to calculate the spectral reflection spectrum of the optical body 10 . The simulation method uses the RCWA method. Also, set the asymmetric area ratio to 0.95. In addition, the parameters used in the simulation are as follows. Structure configuration: six square grid Polarized light: no polarized light Refractive index: 1.52 Grid spacing (dot pitch): 250nm Structure height (height of convex portion): 180nm

The results are shown in Figure 16. The horizontal axis of FIG. 16 shows the wavelength of the incident light, and the vertical axis shows the spectral reflectance of the optical body 10 . As a result, it was confirmed that the spectral reflectance with respect to the wavelength of 400 to 650 nm is approximately 0.1 to 0.45%. In addition, the spectral reflectance with respect to the wavelength of 550 nm is 0.15%. Therefore, it was confirmed that the optical body 10 has high anti-reflection properties over a wide wavelength band.

In addition, the base ratio was measured using commercially available data analysis software (Wolfram Co., Ltd. Mathematica, the same below). The bottom surface ratio is a ratio of the bottom area of all recessed portions 14 to the total area of the surface of the base material 11 (that is, the surface on which the uneven structure 12 is formed). As a result, the floor ratio is a larger value such as 8.0%.

In this way, in Embodiment 1, even if the convex portions 13 do not overlap each other (that is, the base ratio is large), high anti-reflective properties can still be obtained. The inventor believes that such anti-reflective properties can be obtained because the convex portion 13 has an asymmetric shape in the direction of arrow B.

<2. Example 2> (2-1. Production of optical body) The optical body 10 was produced by performing the same process as in Example 1, except that the conditions for producing the optical body 10 were changed as follows. Specifically, the pulse shape of laser light 200A is made as shown in FIG. 12 . Furthermore, the output level Iw of the high-output pulse P1 is set to 9.5MW/cm ² , and the output level Ib1 of the low-output pulse P2 is set to 1.6MW/cm ² . In addition, the output time t2 of the high output pulse P1 is set to 24 ns, and the output time t3 of the low output pulse P2 is set to 2*t1-t2=16 ns.

(2-2. Characteristic evaluation) The surface structure of the optical body 10 was confirmed using SEM and TEM. As a result, it was confirmed that the uneven structure 12 was formed on the surface of the optical body 10 . In addition, few defects in the concave and convex structure 12 were confirmed. Therefore, it was confirmed that the transferability of the master disk 100 was good. In addition, the dot pitch is 250 nm, and the track pitch is 200 nm.

In addition, the convex portion 13 has an asymmetric shape in the direction of arrow B. Specifically, the area ratio between region X11 and region X12 is 0.83, and the distance T1 is 20 nm. In addition, the height of the convex portion 13 is 180 nm. Furthermore, although the convex portions 13 are adjacent to each other, they are hardly overlapped.

Next, the spectral reflection spectrum of the optical body 10 is calculated by the same method as in Example 1. The result is shown in FIG17. As a result, it can be confirmed that the spectral reflectivity relative to the wavelength of 400-650nm is about 0.01-0.3%. In addition, the spectral reflectivity relative to the wavelength of 550nm is 0.02%.

In addition, after measuring the bottom surface ratio using commercially available data analysis software, the bottom surface ratio is 9.7%, which is greater than the value of Example 1.

Therefore, it can be confirmed that the optical body 10 has a high anti-reflection property with respect to a wide wavelength band. In addition, although the bottom surface ratio is higher than that of Example 1, a high anti-reflection property can still be obtained. The reason can be known that the area ratio of Example 2 is a value within a preferred range.

<3. Comparative Example 1> (3-1. Fabrication of optical body) An optical body was fabricated by performing the same process as in Example 1 except that the conditions for fabricating the optical body were changed as follows. Specifically, the pulse shape of the laser light 200A was set as shown in FIG. 10. Furthermore, the output level Iw of the high output pulse P1 was set to 9.5 MW/cm ² , and the output level Ib of the low output pulse P2 was set to 1.1 MW/cm ² (0.35 mW). Furthermore, the output time t1 of the high output pulse P1 and the low output pulse P2 was set to 20 ns.

(3-2. Characteristic evaluation) Use SEM and TEM to confirm the surface structure of the optical body. The SEM photo is shown in Figure 22. As can be seen from FIG. 22 , it is confirmed that the concave and convex structures (convex portions 500 and concave portions 600 ) are formed on the surface of the optical body. In addition, defects in the concave and convex structure are rarely confirmed. Therefore, it was confirmed that the transferability of the master disk was good. In addition, the dot pitch is 250 nm.

Furthermore, the convex portion 500 is symmetrical in all plane directions. Specifically, the top view shape of the convex portion 500 is a true circle (i.e., the area ratio is approximately 1.0), and the distance T1 is approximately zero. Furthermore, the height of the convex portion is 180 nm. Furthermore, although the convex portions 500 are adjacent to each other, they do not overlap.

Next, the spectral reflection spectrum of the optical body is calculated using the same method as in Example 1. The results are shown in Figure 18. As a result, it was confirmed that the spectral reflectance relative to the wavelength of 400 to 650 nm is approximately 0.1 to 0.55%. In addition, the spectral reflectance becomes particularly high in the 450~550nm wavelength band. In addition, the spectral reflectance with respect to the wavelength of 550 nm is 0.29%.

In addition, after measuring the bottom surface ratio using commercially available data analysis software, the bottom surface ratio was 10%.

Therefore, the spectral reflectivity of the optical body is higher than that of the entire embodiment 1. In addition, the spectral reflectivity is particularly high in the wavelength band of 450 to 550 nm. Compared with the embodiment 1, due to the large bottom surface ratio, it can be seen that the reflection of the incident light is generated at the bottom surface of the concave portion 14. In addition, in actual measurement, due to defects in the concave-convex structure, the spectral reflectivity becomes higher than the value shown in Figure 18 (refer to Figure 23).

<4. Comparative Example 2> (4-1. Fabrication of optical body) An optical body was fabricated by performing the same process as in Comparative Example 1 except that the output level Iw of the high output pulse P1 was set to 11.0 MW/cm ² .

(4-2. Characteristic evaluation) The surface structure of the optical body was confirmed by SEM and TEM. As a result, it was confirmed that a concave-convex structure was formed on the surface of the optical body. However, the convex parts overlapped each other to a large extent, and defects of the concave-convex structure were seen everywhere. In addition, the dot pitch was 250nm.

Furthermore, the convex portion is symmetrical in all surface directions. Specifically, the top view shape of the convex portion is a true circle (i.e., the area ratio is approximately 1.0), and the distance T1 is approximately zero. Furthermore, the height of the convex portion is 180 nm. Next, the spectral reflection spectrum of the optical body is calculated by the same method as in Example 1. The results are shown in FIG19 . As a result, it can be confirmed that the spectral reflectivity relative to the wavelength of 400~650nm is approximately 0.01~0.3%. Furthermore, the spectral reflectivity relative to the wavelength of 550nm is 0.02%. However, the spectral reflectivity is ultimately only a result of simulation. As mentioned above, defects of the concave-convex structure can be seen everywhere in Comparative Example 2. Therefore, it can be expected that the actual spectral reflectivity becomes higher than that of FIG19 .

Furthermore, after measuring the base ratio using commercially available data analysis software, the base ratio is a very small value of 5.5%. In Comparative Example 2, since the convex portions greatly overlap each other, the bottom surface ratio becomes smaller. Therefore, the spectral reflectance in the simulation is a good value. However, after actually observing the uneven structure, it can be expected that the actual spectral reflectance will be higher than that in Figure 19 because defects in the uneven structure can be seen everywhere. In other words, when the convex portions 13 are overlapped to a large extent as in Patent Document 4, it is expected that the spectral reflectivity will decrease due to defects in the uneven structure.

<5.Example 3> (5-1. Production of optical body) The optical body 10 was produced by performing the same process as in Example 2, except that the output time t2 of the high-power pulse P1 was randomly changed to between 22 and 25 ns while exposure was performed.

(5-2. Characteristic evaluation) The surface structure of the optical body 10 was confirmed by SEM and TEM. The SEM photograph is shown in FIG21. As a result, it can be confirmed that a concave-convex structure 12 is formed on the surface of the optical body 10. In addition, almost no defects of the concave-convex structure 12 were confirmed. Therefore, it can be confirmed that the transferability of the master 100 is good. In Example 4, the concave-convex is randomly arranged. Therefore, the combination of the majority of adjacent convex portions 13 is selected, and the arithmetic mean of the pitches is calculated as the average period. As a result, the average period is 250nm.

In addition, the convex portion 13 has an asymmetric shape in the direction of arrow B (the up-and-down direction in FIG. 21 ). Specifically, the area ratio between region X11 and region X12 is 0.83, and the distance T1 is 25 nm. In addition, the height of the convex portion 13 is 180 nm. In addition, the convex portions 13 hardly overlap each other.

Next, the spectral reflection spectrum of the optical body 10 is actually measured. The measurement system uses JASCO V-550. The results are shown in Figure 23. For comparison, the actual measurement data of Example 1 and Comparative Example 1 are also shown in FIG. 23 . As a result, it was confirmed that the spectral reflectance with respect to the wavelength of 350 to 800 nm in Example 3 was approximately 0.08 to 0.2%. In addition, the spectral reflectance with respect to the wavelength of 550 nm is 0.09%. Therefore, it was confirmed that the optical body 10 has high anti-reflection properties over a wide wavelength band. In addition, it was confirmed that the spectral reflectance of Example 1 was also approximately 0.2% or less, and that Example 3 had higher antireflection properties than Example 1. This reason can be considered to be that the convex portions 13 are randomly arranged.

In addition, after measuring the bottom surface ratio using commercially available data analysis software, the bottom surface ratio was 10%.

<6.Example 4> (6-1. Production of optical body) A transfer film on which the master concave and convex structure 120 of the master 100 produced in Example 1 was transferred was produced. Furthermore, the optical body 10 was produced by performing the same process as in Example 1, except that the transfer film was used instead of the master 100 .

(6-2. Characteristic evaluation) The surface structure of the optical body 10 was confirmed by SEM and TEM. As a result, it was confirmed that a concave-convex structure 12 was formed on the surface of the optical body 10. The CC cross section of the concave-convex structure 12 was the shape shown in FIG. 7. In addition, almost no defects of the concave-convex structure 12 were confirmed. Therefore, it was confirmed that the transferability of the master 100 was good. In addition, the dot pitch was 250nm and the track pitch was 200nm.

In addition, the recess 14 has an asymmetric shape in the direction of arrow B. Specifically, the area ratio between region X11 and region X12 is 0.9, and the distance T1 is 15 nm. In addition, the depth of the recessed portion 14 is 180 nm. In addition, the recessed portions 14 hardly overlap each other.

Next, the spectral reflection spectrum of the optical body 10 is calculated using the same method as in Example 1. The results are shown in Figure 24. As a result, it was confirmed that the spectral reflectance relative to the wavelength of 400 to 650 nm is approximately 0.05 to 0.3%. In addition, the spectral reflectance with respect to the wavelength of 550 nm is 0.10%. Therefore, it was confirmed that the optical body 10 has high anti-reflection properties over a wide wavelength band.

The bottom surface ratio measured by commercially available data analysis software was 9.8%. The bottom surface referred to here is the top surface (upper end surface) of the convex portion 13 in the optical body 10 obtained when the bottom surface of the transfer film used in the master is replaced.

<7. Example 5> (7-1. Preparation of optical body) Except that the conditions for preparing the optical body 10 are changed as follows, the optical body 10 is prepared by performing the same treatment as in Example 1. Specifically, a mold release agent of an inorganic material system is applied on the master plate concavo-convex structure 120.

(7-2. Characteristic evaluation) The surface structure of the optical body 10 was confirmed by SEM and TEM. As a result, it was confirmed that a concave-convex structure 12 was formed on the surface of the optical body 10. In addition, almost no defects of the concave-convex structure 12 were confirmed. Therefore, it was confirmed that the transfer property of the master 100 was good. In addition, the dot pitch was 250nm and the track pitch was 200nm.

In addition, the convex portion 13 has an asymmetric shape in the direction of arrow B. Specifically, the area ratio between area X11 and area X12 is 0.97. In addition, the height of the convex portion 13 is 180 nm, and the distance T1 is 8 nm. In addition, although the convex portions 13 are adjacent to each other, they are hardly overlapped. The difference in area ratio from Example 1 is considered to be due to a change in the coating state of the release treatment agent.

Next, the spectral reflection spectrum of the optical body 10 is calculated by the same method as in Example 1. The result is shown in FIG25. As a result, it can be confirmed that the spectral reflectivity relative to the wavelength of 400-650nm is about 0.15-0.5%. In addition, the spectral reflectivity relative to the wavelength of 550nm is 0.17%.

In addition, after measuring the base ratio using commercially available data analysis software, the base ratio was 8.0%, the same value within the error range of Example 1. The integration results are shown in Table 1. Furthermore, in Table 1, the 550 nm reflectance values of Examples 1, 2, 4, 5, and Comparative Examples 1 and 2 are simulated values, and the 550 nm reflectance values of Example 3 are actual measured values. In addition, Table 1 also shows the displacement ratio. Therefore, it can be confirmed that the optical body 10 of the embodiment has high anti-reflection properties over a wide wavelength band.

[Table 1]

The preferred embodiments of the present invention are described in detail above with reference to the attached drawings, but the present invention is not limited to the embodiments. As long as a person with ordinary knowledge in the technical field to which the present invention belongs can think of various changes or modifications within the scope of the technical concept described in the scope of the patent claim, it should be understood that these also belong to the technical scope of the present invention.

3a: Transfer film 10: Optical body 11: Substrate 12: Concavoconvex structure 13,500: Convex part 13a: Vertex 14,600: Concave part 100: Master 110: Master substrate 120: Master concavoconvex structure 200: Exposure device 200A: Laser light 201: Laser light source 203: First lens 205: Photodiode 207: Focusing lens 209: Photoelectric deflection element 211: Collimator lens 213: Second lens 220: Moving optical stage 221: Beam expander 223: Field lens 225: Rotating shaft motor 227: Turntable 230: Control mechanism 231: Formatter 233: Driver 300: Transfer device 301: Substrate supply roller 302: Take-up roller 303,304: Guide roller 305: Roller 306: Stripping roller 307: Coating device 309: Light source 310: Uncured resin layer A: Midpoint (center point) B,R: Arrow CC: Cross section Ib: Low-level laser light Iw: High-level laser light Ib1,Ib2: Output level L1,L2: Straight line L12: Dot pitch L13: Track pitch P1: High output pulse P2: low output pulse r: radius t1, t2, t3: output time T1: distance X: quadrilateral X1: line segment X11, X12: area

FIG. 1 is a plan view showing an example of the appearance of an optical body of an embodiment of the present invention. FIG. 2 is a CC cross-sectional view of the optical body of the embodiment of FIG. 1. FIG. 3 is an explanatory view for explaining a method of calculating the area ratio of a convex portion. FIG. 4 is a plan view showing a modified example of a concave-convex structure. FIG. 5 is a plan view showing a modified example of a concave-convex structure. FIG. 6 is a microscope photograph showing a modified example of a concave-convex structure. FIG. 7 is a side cross-sectional view showing a modified example of a concave-convex structure. FIG. 8 is a stereoscopic view showing an example of the appearance of a master disk of the present embodiment. FIG. 9 is a block diagram showing an example of the structure of an exposure device. FIG. 10 is a timing diagram showing a known example of the pulse shape of laser light. FIG. 11 is a timing diagram showing an example of the pulse shape of the present embodiment. FIG. 12 is a timing diagram showing an example of the pulse shape of the present embodiment. FIG. 13 is a timing diagram showing an example of the pulse shape of the present embodiment. FIG. 14 is a timing diagram showing an example of the pulse shape of the present embodiment. FIG. 15 is a schematic diagram showing an example of a transfer device for manufacturing an optical body by roll-to-roll method. FIG. 16 is a graph showing the reflection spectrum of the optical body of Embodiment 1. FIG. 17 is a graph showing the reflection spectrum of the optical body of Embodiment 2. FIG. 18 is a graph showing the reflection spectrum of the optical body of Comparative Example 1. FIG. 19 is a graph showing the reflection spectrum of the optical body of Comparative Example 2. FIG. 20 is a microscope photograph showing the appearance of the optical body of Example 1. FIG. 21 is a microscope photograph showing the appearance of the optical body of Example 3. FIG. 22 is a microscope photograph showing the appearance of the optical body of Comparative Example 1. FIG. 23 is a graph showing the reflection spectrum of the optical body of Examples 1, 3 and Comparative Example 1. FIG. 24 is a graph showing the reflection spectrum of the optical body of Example 4. FIG. 25 is a graph showing the reflection spectrum of the optical body of Example 5. FIG. 26 is a schematic diagram for explaining the lower limit of the area ratio of the top view shape of the convex portion.

10: Optical body

13: convex part

13a: vertex

14: concave part

A: Midpoint (center point)

B:arrow

CC: Cross-section

L12: point pitch

L13: Track pitch

Claims (18)

An optical body having a concave-convex structure, wherein the concave-convex structure is formed by arranging a plurality of convex or concave structures at an average period below the wavelength of visible light, and when the top view shape of the structure is divided into two regions by a straight line, the respective areas are different; the straight line is a quadrangle circumscribed to the structure that is divided into two equal parts along the direction of the trajectory in which the structure is arranged, and the area ratio of the two regions obtained by dividing the area of the smaller region by the area of the larger region is greater than 0.83 and less than 0.97. The optical body of claim 1, wherein the base ratio of the structure is 8% or more and 10% or less. As in claim 1, the optical body, wherein the aforementioned structure has an asymmetric shape in the aforementioned orbital direction in the plane direction perpendicular to the aforementioned optical body thickness direction, and has a symmetric shape in the direction perpendicular to the aforementioned orbital direction; the vertical cross-sectional shape of the aforementioned structure is a shape inclined toward the aforementioned orbital direction, and the top view shape of the aforementioned structure has an asymmetric skewed shape in the aforementioned orbital direction. Such as the optical body of claim 3, wherein the aforementioned area ratio is 0.95 or less. As in claim 1, the optical body, wherein the vertical cross-sectional shape of the aforementioned structure has an asymmetric shape in the aforementioned orbital direction. As in claim 5, the position of the vertex of the vertical cross-sectional shape of the aforementioned structure is displaced in the aforementioned orbital direction relative to the center point of the aforementioned structure in the aforementioned orbital direction. Such as the optical body of claim 6, wherein the displacement ratio of the displacement amount of the aforesaid vertex position divided by the point pitch of the aforesaid structural body is 0.03 or more. As in claim 7, the optical body, wherein the displacement ratio is greater than 0.03 and less than 0.5. As in claim 1, the arrangement pitch of the aforementioned structure in the aforementioned track direction is different from the arrangement pitch of the aforementioned concave-convex structure in a direction perpendicular to the aforementioned track direction. The optical body of claim 1, wherein the structure has a convex shape. The optical body of claim 1, wherein the structure has a concave shape. The optical body of claim 1, wherein the structural system is composed of a cured product of curable resin. The optical body of claim 1, wherein the adjacent structures are connected to each other. An optical body as claimed in claim 1, wherein the aforementioned structures are arranged periodically in the aforementioned orbital direction. The optical body of claim 1, wherein the structures are randomly arranged in the track direction with an average period below the wavelength of visible light. A master disk having a surface formed with a complementary shape of a concave-convex structure as in any one of claims 1 to 15. As in claim 16, the master disk is in the shape of a plate, a cylinder, or a column. A method for manufacturing an optical body, using a master disc as claimed in claim 16 as a transfer mold and forming the aforementioned concave-convex structure on a substrate.

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